What are the symptoms?
Patients with Raynaud's phenomenon classically report intermittent triphasic changes in the colour ofthe extrem ities(fingers, toes, nose, cheeks, and ears-usually trig gered by cold exposure or emotional stress-from white(owing to vasoconstriction), to blue(tissue hypoxia), to red on rewarming(reperfusion) (figs 1 and 2). Colour changes are associated with tightness in the first two stages and burning pain in the reperfusion stage. Not all of the three phases are needed to make a diagnosis. Colour changes occur intermittently and tend to resolve when the digits are rewarmed. An attack may last for min utes to hours. Patients with secondary Raynaud's phe- nomenon are more likely to have severe disease, which, if left untreated, can progress to ulceration or gangrene of extremities.